The objective of this study is to investigate a new, inexpensive, portable, blood pressure feedback device which may make it possible for hypertensives to learn and practice lowering their pressures with optimal frequency, in the relevant home and work situations, and with greater hope of generalized effect to non-feedback situations. Laboratory feedback of blood pressure levels have been shown to enable normal subjects to reduce their systolic and diastolic pressures up to 15-30% in the laboratory situation. Four of five recent studies with essential hypertensives obtained systolic and/or diastolic reductions up to 18-30%. But laboratory biofeedback has been prohibitively expensive for any large-scale therapeutic application, and first results indicating that laboratory learning of blood pressure reduction generalizes to the hypertensive patient's daily life and persists after training need to be confirmed. Essential hypertension volunteers from a hospital hypertension clinic will be trained in the use of the device, asked to practice lowering their systolic pressure regularly at home and at work and keep records of practice pressures for four weeks, coming in weekly for laboratory pressure readings. One control group will be treated virtually identically, but will only be trained and instructed to take their pressures, not reduce them. Another control group will receive no treatment. Home records should indicate whether patients have learned to use the feedback device to lower their pressures. Comparison of inital, four weekly and final laboratory pressure readings should show whether learning has generalized to situations in which there is no feedback. A final laboratory recording session with feedback should confirm any learning of control and/or identification of direction of pressure changes.